US 11,942,379 B1
Inspection method for detecting a defective bonding interface in a sample substrate, and measurement system implementing the method
Dario Alliata, Montbonnot-Saint-Martin (FR); and Jean-François Boulanger, Montbonnot-Saint-Martin (FR)
Assigned to Unity Semiconductor, Montbonnot-Saint-Martin (FR)
Filed by Unity Semiconductor, Montbonnot-Saint-Martin (FR)
Filed on Jul. 26, 2023, as Appl. No. 18/359,661.
Claims priority of application No. 22315316 (EP), filed on Dec. 8, 2022.
Int. Cl. H01L 21/66 (2006.01); G01N 21/95 (2006.01)
CPC H01L 22/12 (2013.01) [G01N 21/9501 (2013.01); H01L 22/20 (2013.01)] 16 Claims
OG exemplary drawing
 
1. An inspection method for detecting a defective bonding interface in a sample substrate comprising at least one element disposed on a support, a bonding interface being defined between the at least one element and a main face of the support, an outer surface of the at least one element being exposed on a front side of the sample substrate and defining, at least in part, an exposed surface of the sample substrate, the inspection method comprising:
placing the sample substrate in a measurement system;
establishing, with the measurement system, an inclination map of the exposed surface, the inclination map comprising a plurality of local inclination measurements relative to a reference surface corresponding to the main face of the support;
analyzing the inclination map, the analyzing comprising:
calculating inclinations of predefined zones of the exposed surface, an inclination of a zone being a representative value of a local inclination measurement associated with the zone;
identifying among the predefined zones at least one identified zone having an inclination deviating by more than a given threshold from the inclination of the reference surface; and
detecting a presence of a defective bond between the at least one element and the support in the at least one identified zone.